Grafting of maleic anhydrides to polymers by use of a free radical initiator is known, and polyketones are often included as a polymer to which such grafting could be accomplished. U.S. Pat. No. 4,927,888 is exemplary of such art. Grafting of such monomers as maleic anhydride to polymers is often done to impart sites for ionic bonding for to increase the hydrophilic nature of the compound, to provide a reactive site for further modification, or to improve bonding to polar substrates. The use of free radical initiators to accomplish such grafting results in considerable chain scission of the polymer, and the extent to which a monomer such as maleic anhydride can be incorporated onto the polymer chain is limited to an amount which is less than what would be desired for many uses.
U.S. Pat. No. 4,026,967 discloses an apparatus and method for grafting monomers such as maleic anhydride to polymers having backbones of ethylene and copolymers of ethylene and alpha olefins. Polyketones are included as suitable copolymers for such grafting. A dispersed plug flow reactor at 275.degree. C. to 550.degree. C. is used to achieve the grafting. The mechanism for the grafting is described as thermocracking, and as such considerable chain scission would be expected, and achieving more than two grafted monomer units on each remaining polymer molecule would not be expected.
It would be desirable to have a polyketone to which a significant amount of a polar monomer was grafted. It would further be desirable to have such a grafted polymer which was not subjected to significant chain scission. It is therefore an object of the present invention to provide such a polymer and to provide a method to produce such a polymer.